Income Taxes - Components of Income Tax Benefit (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal									$ (69,204)	$ 46,331	$ 25,417
State and local									1,870	8,759	979
Current income tax expense (benefit)									(67,334)	55,090	26,396
Deferred
Federal									(153,598)	(159,171)	(33,788)
State and local									(39,728)	(37,155)	(1,620)
Deferred income tax benefit									(193,326)	(196,326)	(35,408)
Total income tax benefit	$ 49,069	$ (56,357)	$ (147,183)	$ (106,189)	$ (91,056)	$ (54,630)	$ 23,120	$ (18,670)	$ (260,660)	$ (141,236)	$ (9,012)